<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<!--[if lt IE 9]>
    <script src="jquery-1.9.0.js"></script>
<![endif]-->
		<!--[if gte IE 9]><!-->
		<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
		<!--<![endif]-->
		<script type="text/javascript">
			$(document).ready(function() {
				$("input").focus(function() {
					$("span").css("display", "inline").fadeOut(2000);
				});
			});
		</script>
		<style>
			span {
				display: none;
			}
		</style>
		</script>
	</head>

	<body>
		<input>
		<span>请输入你的电话号码?</span>
		<p>点击输入框获取焦点。</p>

	</body>

</html>